﻿<!DOCTYPE html>
<html>
     <head>
          <meta charset="UTF-8">
          <title></title>
     </head>
		<script>
			//window 全局对象
			var num = 100;
			
			
			function test(num){
				
				console.log(++num);
				console.log(window.num);
			}
			test(num);
			
			console.log(window.test);
			//所有的全局变量，都是属于window对象的
			
			window.alert()
			window.parseInt()
			window.parseFloat()
			window.Number()
			window.String();
			
			window.document
		</script>
     <body>
		<button onclick="alert(window.innerWidth)">关闭</button>
     </body>

</html>
